👤 Öznur Özge Özcan

Nerve Guidance Conduits (NGCs) are crucial for reducing trauma during nerve repair, directing axonal growth, and preventing scar tissue formation. In this study, tubular functional NGCs were developed based on vertically aligned electrospun poly(lactic-co-glycolic acid) (PLGA) nanofibers (vNGC). They were functionalized by conjugating them with bioactive mimetic peptides: a laminin-derived peptide (LD-BP) to promote vascularization, and nerve growth factor (NGF-BP) and brain-derived neurotrophic factor (BDNF-BP) mimetic peptides to support neural differentiation. The vascular differentiation of HUVECs in response to LD-BP, and the neuronal differentiation of PC12 cells in response to NGF-BP and BDNF-BP, were assessed. The results demonstrated that this approach enabled the fabrication of tubular vNGCs with various diameters, and that vertically aligned PLGA nanofibers significantly improved their structural integrity. Furthermore, BP-conjugated vNGCs outperformed non-conjugated control groups in promoting both vascular and neural differentiation. Importantly, peptide conjugation did not induce cytotoxicity or significantly alter the biodegradability of the vNGCs, supporting their suitability for biomedical applications. Finally, bifunctional vNGCs (BiF-vNGCs), conjugated with LD-BP, NGF-BP, and BDNF-BP, were tested in a rat model of sciatic nerve injury. The BiF-vNGCs showed superior performance compared to unmodified vNGC, Control and s-Control groups, effectively promoting vascularization and neural regeneration in vivo, offering a viable alternative to conventional nerve regeneration methods. Show less

Chronic stress induces sensorimotor, cognitive, and neuroendocrine alterations, particularly in females who exhibit heightened vulnerability to stress-related disorders. This study tested the hypothesis that chronic quetiapine administration during ongoing unpredictable chronic mild stress (UCMS) would attenuate stress-induced impairments in sensorimotor gating, recognition memory, and HPA-axis–related biochemical markers in female rats. Adult female Wistar rats were exposed to a 9-week UCMS paradigm, with quetiapine (10 mg/kg/day, i.p.) administered during the final 3 weeks. Behavioral outcomes were assessed using prepulse inhibition (PPI), startle reactivity, and the Novel Object Recognition (NOR) test. Serum and hippocampal corticosterone and BDNF levels were quantified by ELISA. Chronic stress significantly reduced PPI and recognition memory performance and increased serum and hippocampal corticosterone levels. Quetiapine treatment improved PPI and startle responsiveness, restored NOR discrimination index values, and partially attenuated stress-induced corticosterone elevations. Hippocampal BDNF levels were elevated in stressed animals and were modulated toward intermediate levels following quetiapine treatment. These findings indicate that chronic quetiapine administration mitigates behavioral and neuroendocrine alterations induced by prolonged stress in female rats. [Image: see text] The online version contains supplementary material available at 10.1007/s11011-026-01834-8. Show less

Amyloid precursor protein (APP) is a brain-rich, single pass transmembrane protein that is proteolytically processed into multiple products, including amyloid-beta (Aβ), a major driver of Alzheimer disease (AD). Although both overexpression of APP and exogenously delivered Aβ lead to changes in sleep, whether APP processing plays an endogenous role in regulating sleep is unknown. Here, we demonstrate that APP processing into Aβ40 and Aβ42 is conserved in zebrafish and then describe sleep/wake phenotypes in loss-of-function Show less

Imidazole derivatives display extensive applications in pharmaceutical chemistry and have been investigated as bioactive compounds for medicinal chemistry. In this study, besides the starting materials ( Show less

To summarize the nutritional supplementation on biochemical parameters, cognition, function, Alzheimer's Disease (AD) biomarkers and nutritional status. PubMed, Web of Science, Korean Journal Database, Russian Science Citation Index, SciELO Citation Index, Cochrane Library and Scopus databases were searched until 16 April 2021. 22.193 records in total were reached according to inclusion and exclusion criteria. Included Studies were evaluated through the Modified Jadad Scale and gathered under four subheadings. Forty-eight studies with a total of 7009 AD patients were included. Souvenaid, ONS (368 ± 69 kcal), Vegenat-med, 500 mg Resveratrol, ONS (200 mL) were effective nutritional supplements on promoting weight gain and protecting malnutrition status but showed conflicting results in Body mass index, Mid-Upper-Arm Circumference and Triceps Skin Fold Thickness. ONS and a lyophilized whole supplementation Vegenat-med intake made an increase in MNA scores. While all nutritional supplements showed controversial results in biochemical parameters but caused a decrease in Hcy levels which caused reductions in brain Aβ plaque (increase serum Aβ), p-Tau and cognitive improvement. Folic acid and vitamin D decreased serum APP, BACE1, BACE1mRNA. Resveratrol, Better designed trials with holistic measures are needed to investigate the effect of nutritional support on the AD biomarkers, cognitive status, biochemical parameters and functional states. Also, more beneficial results can be obtained by examining the simultaneous effects of nutritional supplements with larger sample groups. Show less